Engine



AP 15p 1947- c. E. FRANK :TAL V2,419,066

ENGINE Filed Nov. 22, 1943 3 Sheets-Sheet 1 April `15, 1947.

\ Filed Nov. 22, 1943 E. FRANK E'rAl.

ENGINE 3 Sheets-Sheet 2 I 'EI l\\ \\\Al lllll\ APIil 15 1947- l c. E. FRANK-rm. c 2,419,066

' l `ENGINE r I x mea Nov. 22 194s vs sheets-sheet s zal' lll/l ll l g5 I /d (g AIN VEN TORS. @Zd/epee E.' 75u Patented Apr. 15,1947

ENGINE Clarence E.

Detroit, Mich.,

Michigan Frank and Raymond A. Wyatt,

assignors to Briggs Manufacturing Company, Detroit, Mich.,

a corporation of Application November 22, 1943, Serial No. 511,276

(Cl. 12S-173) 14 claims.

This invention relates to internal combustion engines and especially to engines of the class in which a substantial portion of the combustion space at the time of ring is formed by a chamber within a rotatable valve mounted in the cylinder head or other housing structure associated with the engine cylinder. An important object of the present invention is to provide an improved liquid cooledengine of the foregoing class which will be eflicient in operation, compact in construction and easy to assemble as well as dis-assemble for the purpose of providing ready access to the pistons when overhauling the engine.

In the construction of a satisfactory engine of the foregoing type which will perform eiciently and economically over sustained periods of operation, the most serious problems encountered have been in connection with the lubrication of the rotatable valve, the cooling of the valve and associated parts of the engine, the control of bearing `loads' between the valve and its housing and the construction of the enacting bearing surfaces between the valve and its housing so as to reduce friction as well as loss of power during operation to a minimum.

The present invention deals mainly with the cooling system for the engine and, while contemplating the solution of problems relating to the cooling of the engine by a liquid medium, it also contemplates important improvements in the construction of the engine by which not only assembly and overhauling operations are facilitated but also more efficient control of expansion of the valve and valve housing is achieved thereby maintaining during operation greater uniformity in the running clearances between the bearing surfaces of the valve and housing which sustain considerable loads, especially at the time firing occurs and during the power stroke of the piston.

Accordingly, an object of the present invention is to provide a liquid cooled engine of improved construction adapted to overcome diculties heretofore encountered and which may be operated eiiciently while attaining relative high performance characteristics.

A further object of the invention is to provide an engine having a. rotatable valve forming a substantial portion of the combustion chamber and in which the engine is liquid cooled in an emcient and improved manner.

Another object of the invention lis to provide an engine having a rotatable valve in the head thereof and a liquid cooling jacket associated with the cylinder and extending into the head and in which the jacket surrounding the cylinder is separable at a point below the piston pin when the piston is at its extreme outer position in the cylinder, the improved construction being such that the cylinder head, cylinder and a portion of the jacket surrounding the cylinder are removable as a, unit when overhauling the engine.

A further object of they invention is to provide a cylinder head constructed for mounting and operation therein of a rotatable valve, preferably of rusto-conical shape, and in which the cylinder head is constructed in improved manner to provide emcient cooling of the valve and its associated parts as well as the exhaust conduit by means of a liquid coolant. I

Another object of the invention is to provide improved means for assembly and attaching together the cylinder and cylinder head, the same being accomplished in such improved manner as to eiect control of the expansion of the housing for the rotatable valve during operation, thereby maintaining greater uniformity inthe operating clearance between the valve and its bearing surfaces and reducing loss of lubricant due to leakage past' such surfaces.

Still a further object of theL invention is to provide improved means for supporting and mounting the rotatable valve as well as improved means for driving the valve.

Other objects of this invention will appear in the following description and appended claims, reference being had to the acompanyng drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a fragmentary sectional elevation illustrating a portion of a multi-cylinder engine embodying the present invention.

Fig. 2 is a fragmentary sectional elevation illustrating the driving mechanism for the rotatable valve or valves of the engine.

Fig". 3 is a section taken substantially through lines 3 3 of Fig. 1 looking in the direction of the arrows.

Fig. d is a fragmentary sectional elevation, somewhat similar to Fig. l but on a reducedvscale, showing the manner in which the cylinder head and cylinder may be removed as a unit when overhauling the engine.

Fig.. 5 is a fragmentary sectional view illustrating a somewhat modied construction.

Before explaining in detail the present invention it is to be understood that the invention is not limited in' its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways.

Also it is to be understood that the phraseology f or terminology employed herein is for the purpose of description and not of limitation.

The present invention is especially applicable to engines of the class having rotatable valves, preferably but not necessaritly rotating continuously in one direction, for controlling the intake and ring of the fuel charge and for exhausting the products of combustion. In the illustrated embodiment of the invention, exemplitying one desirable adaptation thereof, 9, rc1-.ata-

ble valve of the frusto-.conical type is mounted in the cylinder head and is formed with substantially all or at least ,the major portion of theI combustion chamber. The valve or rotor lis formed with an opening or port in the side of the valve adapted to register with intake and exhaust passages and an ignitionv device during operation, there being an opening or portat the inner end or bottom of the rotor communicating at all times with the cylinder. The present invention deals especially with the cooling of the engine and provides an improved construction for circulating a liquid coolant around the cylinder and through the cylinder head whereby the temperatures of the cylinder, cylinder head and valve are emciently controlled and adequate dissipation of heat is obtained especially at localities tending to become overheated.

In the drawings we have illustrated, by way of example, one embodiment of the invention as applied to an internal combustion engine of the spark ignition type. However, it will be understood that the invention is not limited to an engine in which combustion is initiated by spark ignition. For most uses the engine is of the multi-cylinder type but for the purposes of simpliilcation a single cylinder unit of the engine is illustrated in the present embodiment, it being understood that the remaining cylinders and associated parts are identical to the structure herein shown and described.

Referring to the drawings, the present engine comprises a cylinder within which a suitable piston 2| is mounted for reciprocation. The piston is connected in the usual manner through a wrist pin 2|a and connecting rod 22 to the crankshaft 23'of the engine. Surrounding a portion of the 'cylinder 23 is a cylindrical Jacket 24 which is rigidly secured to the crankcase or forms substantially an integral portion of the crankcase. This jacket member 24 has an extended portion spaced from the wall of the cylinder 20 to provide a water cooling space or chamber 25 extending entirely around the cylinder. The cylindrical jacket 24 terminates within the height of the cylinder 20 at a point somewhat below or inward of the wrist; pin 2|a when the piston is at the extreme outer end of its stroke.

The lower or inner end of the cylinder 20 is formed with an annular rib 20a forming a pilot portion slidable into and having a smooth ilt within the inner cylindrical wall ofthe lower section 24a of the jacket member 24, the rib 20a carrying sealing rings 26 to prevent leakage of :the coolant between the juxtaposed surfaces of the portions 20a and 24a.

The engine is provided with a cylinder head 21 which is cast with a depending wall or skirt, 28 extending below the outer end of the cylinder and spaced from the cylinder wall to provide a liquid cooling space or chamber 29 adapted to form a continuation of the chamber 25. The lower or inner end of the wall or skirt 28 of the cylinder head is formed with an annular rib 28a adapted to cooperate with a corresponding ribbed por-L tion 24h formed at the outer end of the jacket member 24. When the cylinder head is assembled the ribbed portion 28a is drawn down tightly against .the ribbed portion 24h, there being a gasket 30 interposed between the juxtaposed sur- .faces of these portions adapted to be compressed lto provide a liquid tight joint.

In the embodimentI of Fig. 1 the outer end of the cylinder is formed with an outwardly extend- .ing annular ange Zlib` extending' in juxtaposed relation to an annular boss 2'1a1'formed on the cylinder head. The overlapping portions 21a and 20o are secured together by means of a series of bolts 3| which are effective to clamp the cylinder head and cylinder tightly together, there being a gasket 32 interposed between the adjacent surfaces of theportions 21a and 20h. This gasket may be of thek copper-asbestos type capable of sustaining high temperatures and pressure, and when thebolts 3| are tightened sufllciently the gasket 32 will provide aliquid and gas tight joint. The cylinder head is formed with series of lugs or ribs- 33 and 34 bored to receive bolts 38 extending from bosses 35 on the jacket member 24 which, as stated, is fixed to the crankcase. The cylinder head may be drawn down tightly to the crankcase or jacket member 24 by nuts 33a on the bolts 36, thus connecting the jackets 24 and 28 tightly together at the water tight joint formed by the gasket 30.

'I'he annular flange 20h of the cylinder is formed with an annular recess 31 at its inner side forming a vertical shoulder 33. The cylinder head is provided with a valve housing 39 which is integral with the portion 21a and has an annular portion tting into the recess 31 and abutting against the shoulder 38, as clearly shown in Fig. 1. Thus, the inner end of the valve housing portion 39 of the cylinder head and the outer end of the cylinder 20 are not only rigidly bolted together but also have interiitting portions as a result of which it is possible to utilize the cylinder 20 as a means for positively controlling the thermal expansion of the valve housing during operation.-

'I'hevalve housing portion 39 of the cylinder head is formed with a generally frusto-conical `recess 40 within which is mounted a rotatable yvalve or rotor 4| which is also of generally frustoconical construction having tapering outwardly' converging Walls corresponding generally in shape to the inner walls of the recess 40. The bottom or inner wall 4|a of the valve is preferably tapered so as to correspond substantially to the taper of the piston head, the construction being such that the piston head will approach very closely the bottom of the valve 4| when the piston is at the outer end of its stroke.

The valve member 4| is formed with a side port 43 communicating with the combustion chamber 42 and adapted to register successively during rotation of the valve with` a spark plug 44, an exhaust passage or conduit 45, and an intake conduit or passage 46 in the cylinder head, the direction of rotation of the valve being indicated by the arrow in Fig. 3. As also shown in this figure, the liquid coolant chamber 29 has l extensions 29a in the cylinder head extending substantially around the valve member 4| and also extending along and in the height of the outer walls of the exhaust and intake passages 45 and 46. Another portion 29h of the coolant chamber extends through the dividing wall between these passages. From this construction it will be seen that substantially all portions of the cylinder, cylinder head, valve and intake and exhaust passages, which are subjected to heating during operation, are exposed to the cooling effect of the liquid circulated through the water jackets. The coolant is preferably introduced into the lower end of the chamber 25, circulated upwardly through the communicating chambers, which have a common outlet in the cylinder head.

In addition-itc the side port 43 the valve 4| has a central port or opening t1 at its inner end communicating with the cylinder. The valve member M is also formed with acooling chamber t8' extending entirely around the combustion chamber of the valve member. This cooling chamber is adapted to receive any suitable cooling medium such, sealed into the chamber by means of an expanding plus lita.

In the present embodiment the valve or rotor M is driven at one-half engine or crankshaft speed. It isprovided with a projecting stem t9 through the medium of which the driving mechanism for the valve is connected. The valve housing portion 39 of the cylinder head is provided for example, as metallic sodium, which is "anaocc A 10 extending entirely around the valve and subwith an annular recess 5t in its outer end through which the valve stem t9 extends. Within this recess is located a cup-shaped spring retainer member 5| adapted to receive a compression spring 52 surrounding the valve stem dt. The

outer end of the spring engages a steel coupling Y disk E3, This disk is formed centrally thereof with an annular set of teeth td meshing with corresponding teeth formed on the end of the valve stem t9. The valve stem is tapped to receive a threaded stud or bolt to which carries a nut 56a engageable with the coupling disk 53 and adapted to betightened to draw down the disk and maintain its teeth 5t in constant mesh with the teeth on the outer end of the valve stem. The spring 52 is, therefore, held under constant compression so as to yieldingly hold the valve upwardly within the frusto-conical recess it in the valve housing. The strength of this spring and the amount of preloading thereof is such that the eort exerted by the spring to raise the valve within the valve housing is suicient to substantially offset or `equal the effort exerted during the suction stroke of the piston to draw the valve downwardly and away from its seat.

The coupling disk 53 is providedwith external teeth '05 meshing with internal teeth Sala, on a ring gear 5l. This gear in turn has external teeth 51h meshing with the teeth of a valve driving gear 58 secured to a longitudinally extending top shaft 6i. The cylinder head is formed with a housing 59 provided with a removable closure 6d for housing the driving mechanism located in the cylinder head. Fl'he top shaft 6| at one end thereof carries a gear 62' meshing with a gear t3 secured to the upper end of a tower shaft td. This tower shaft extendsv through a tube or housing t5 and carries at its lower end a gear t@ meshing with a gear 6l secured to the crankshaft 23 of the engine.

It will be noted that the. bottom of 'the valve member dl hasr a downwardly vand outwardly tapering contour @i la corresponding to the tapering contour of the piston head. This tapering bottom portion il a of the valve terminates at a point inward of the outer end of the cylinder wall inan outwardly and .upwardly tapering or bevelled portion 68 which overlies the bevelled end Si@ of ,the cylinder wall. A clearance of a few thousandths of an inch is at all times maintained between the bevelled or tapering bottom portion @d of the valve and the bevelled end 69 of the cylin der wall so` that at no time during operation will the valve contact the end of the cylinder. This clearance will be maintained even during the suction stroke of the piston since, as previously stated, the loading of the spring 52 is sumcient to counteract the downward pull on the valve during the suction stroke.- The valve member is also preferably provided with an exterior relief area stantially lthe height of the side port 43. This annular relief area may be formed either in the valve or in the wall of the valve housing and may be constructed and serve the purposes in accordance with copending application Serial No. 495,260.

The embodiment illustrated in Fig. 5 differs from .the preceding embodiment in that the annular flange 2th on the outer end of the cylinder is" dispensed with a steel ring 1| is utilized in lieu thereof.. This ring 1l may be a solid or a split ring and is provided at the inner side thereof with an annular shoulder l2 adapted to underlap a similar shoulder on the cylinder 20 so that when the bolts Si are tightened the cylinder and cylinder head will be drawn tightly together against the gasket 32.

It will be particularly noted that the joint between the walls of the jacket portions 2li and 28, which joint is defined by the sealing gasket 3Q, lies below the wrist pin 2|a. By virtue of this construction and the manner in which the cylinder and cylinder head are connected together, it is possible in overhauling the engine to remove the piston without disconnecting it from the crankshaft. The improved construction permits the cylinder and cylinder head to be removed as a unit without disturbing the piston, after which the pin 2 la may be withdrawn to permit removal of the piston. The manner in which this can be accomplished is illustrated in Fig. 4. The nuts 36a are first removed from the bolts 36 after which the cylinder head and cylinder may be withdrawn bodily from the cylindrical jacket 2t.

, This will expose the piston suilciently above the outer end of the Jacket member 2t to permitjhe p in 2|a to be withdrawn since the cylindrical jacket 24 terminates at a point below the piston pin when the piston is at its extreme outer position.

Another important feature of the vpresent invention resides in. the manner in which very accurate control of the expansion of the valve housing is achieved. It will be noted that the piston cylinder and the valve housing are surrounded by a jacket within which a liquid coolant is circulated, thus providing substantially uniform dissipation of heat. In preferred practice the cylinder head (including the valve housing) is made of an aluminum alloy whereas the rotary valve and the cylinder are formed of suitable ferrous alloys. Hence, the valve housing will have a greater rate of expansion than either the valve or cylinder, the latter two having substantially the same rate of expansion. VOrdinarily, therefore, the head will tend to expand more rapidly or to a greater degree than the valve, thus increasing the clearances between the valve and valve housing which will have the undesirable result of causing oil leakage especially during the suction stroke of the piston. However, in accordance with the present invention the valve housing has an annular rib seated in the recess 3l of the cylinder and abutting against the shoulder 38. This shoulder acts as a restraining abutment preventing outward movement of the valve housing relative to the cylinder. Hence, a constant control over the expansion of the housing with relation to the cylinder and valve is maintained and the desired operating clearances between the valve 'and valve housing are held substantially uniform during operation. Much improved operation is, therefore. achieved while reducing materially the oil consumption.,

We claim:

1. An internal combustion engine having a cylinder, a reciprocable piston therein, a cylinder head, a rotatable valve mounted in said head, and a jacket forming a space for circulating liquid coolant around the cylinder and said valve, said cylinder head having a skirt forming a portion y of said jacket and extending inwardly of the outer end of the cylinder to a point inward of the piston'pin when the piston is at its outer position in the cylinder.

2. An internal combustion engine having a cylinder, a piston therein, a rotatable valve, a cylinder head `having a housing for said valve and a jacket extending around the housing, said jacket having an integral extension surrounding the outer portion of the cylinder, and a separate cylinder jacket joined to said rst named jacket between the ends of the cylinder.

3. An internal combustion engine havingl a cylinder, a piston therein, a rotatable valve, a cylinder head having a housing for said valve and a jacket extending around the housing, said jacket having an integral extension surrounding the outer portion of the cylinder, and a separate cylinder jacket joined to said first named jackets between the ends of the cylinder, said jackets forming a continuous space around the cylinder for the circulation of a coolant. y

4. An internal combustion engine having a cylinder, a piston therein, a rotatable valve, a cylinder head having a housing for said valve, and a sealed joint between abutting surfaces of the valve housing and cylinder, said valve housing and cylinder having interfitting portions whereby outward movement of the housing due to thermal expansion is restrained by the cylinder.

5. In an internal combustion engine, a cylinder, a cylinder head, a rotatable valve in the head, a cylinder head jacket, and a cylinder jacket joined to the cylinder head jacket, said cylinder at its outer end having a shoulder portion abutting against a portion oithe cylinder head adjacent the inner end .of the valve to restrain lateral expansion of said portion relative to the cylinder.

6. In an internal combustion engine, a cylinder, a cylinder head having a valve housing, a rotatable valve in said housing, a cylinder head liquid cooling jacket extending around said housing, and abutment means on said cylinder engaging a portion of said housing adjacent the inner end of the valve for restraining lateral expansion of the housing relative to the cylinder.

7. In an internal .combustion engine, a cylindera cylinder head having a generally frustoconical valve housing, a rotatable generally frusto-conical valve in said housing, a cylinder head liquid cooling jacket extending around said housing, and abutment means on said cylinder engaging a portion of said housing adjacent the inner end of the valve for restraining lateral expansion of the housing relative to the cylinder.

8. In an internal combustion engine, a cylinder, a cylinder jacket embracing a cylinder, a cylinder head having a housing provided with a generally frusto-conical cavity, a generally frustoconical valve in said cavity, a jacket extending around said housing and joined to said cylinder jacket, and abutting portions on the valve housing and cylinder adapted to restrain lateral expansion of the housing.

9. In an internal combustion engine, a cylinder, a cylinder jacket embracing the cylinder, a cyl- .K 8 inder head having a housing provided with a generally frusto-conical cavity, a generally frustoconical valve in said cavity, a jacket extending around said housing and joined to said cylinder jacket, means for securing said cylinder and valve housing together, and abutting portions on the,valve housing and cylinder adapted to restrain lateral expansion ofthe housing 10. In an internal combustion engine, a cylinder, a cylinder head having a valve housing, a rotatable valve in said housing, a cylinder head liquidcooiing jacket extending around said housing, means for securing said cylinder and valve housing together, and abutment means on said cylinder engaging a portion of said housing adjacent the inner end of the valve for restraining lateral expansion of the housing relative to the cylinder.

' 11. In an internal combustion engine, a cylinder, a cylinder head, a rotatable valve in said head, means for securing said cylinder head and cylinder together, and abutting means on the cylinder and head adjacent the inner end of the valve for restraining lateral expansion of portions of the head adjacent the inner end of the valve.

12. In an internal combustion engine, 'a cylinder, a cylinder head, a rotatable valve in said head, said valve being generally frusto-conical with the larger end of the valve positioned adjacent the outer end of the cylinder, means for securing said cylinder head and cylinder together, and abutting means on the cylinder and head adjacent the inner end of the valve for restraining lateral expansion of portionsof the head adjacent the inner end of the valve.

13. In an internal combustion engine, a cylinder, a cylinder head, a rotatable valve in said head, means for securing said cylinder head and cylinder together, and abutting means on the cylinder and head adjacent the inner end of the valve for restraining lateral expansion of portions of the head adjacent the inner end of the valve, said abutting means being located nearer the axis of the valve than said securing means.

14. In an internal combustion engine, a cylinder head, a rotatable valve in the head, a cylinder terminating in an annular laterally extending flange, a sealing gasket interposed between said ilange and head,- means Ifor securing the ange to the head to compress'said gasket, said flange and head having interiitting abutting portions, and a liquid cooling jacket embracing said cylinder and valve.

CLARENCE E. FRANK. RAYMOND A. WYATT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Romeiser et al Aug. 18, 1925 

